PDBsum entry: 1e6k

Signaling protein

PDB id: 1e6k

Contents

Protein chain

130 a.a. *

Waters ×41

* Residue conservation analysis

PDB id:

1e6k

Name:

Signaling protein

Title:

Two-component signal transduction system d12a mutant of chey

Structure:

Chemotaxis protein chey. Chain: a. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.190 R-free: 0.260

Authors:

M.Sola,E.Lopez-Hernandez,P.Cronet,E.Lacroix,L.Serrano, M.Coll,A.Parraga

Key ref:

M.Solà et al. (2000). Towards understanding a molecular switch mechanism: thermodynamic and crystallographic studies of the signal transduction protein CheY. J Mol Biol, 303, 213-225. PubMed id: 11023787 DOI: 10.1006/jmbi.2000.4507

Date:

18-Aug-00 Release date: 05-Mar-01

Protein chain

P0AE67  (CHEY_ECOLI) -  Chemotaxis protein CheY

Seq: 129 a.a.

Struc: 130 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Cellular component: cytoplasm (1 term)
• Biological process: intracellular signal transduction (7 terms)
• Biochemical function: two-component response regulator activity (3 terms)

DOI no: 10.1006/jmbi.2000.4507

J Mol Biol 303:213-225 (2000)

PubMed id: 11023787

Towards understanding a molecular switch mechanism: thermodynamic and crystallographic studies of the signal transduction protein CheY.

M.Solà, E.López-Hernández, P.Cronet, E.Lacroix, L.Serrano, M.Coll, A.Párraga.

ABSTRACT

The signal transduction protein CheY displays an alpha/beta-parallel polypeptide folding, including a highly unstable helix alpha4 and a strongly charged active site. Helix alpha4 has been shown to adopt various positions and conformations in different crystal structures, suggesting that it is a mobile segment. Furthermore, the instability of this helix is believed to have functional significance because it is involved in protein-protein contacts with the transmitter protein kinase CheA, the target protein FliM and the phosphatase CheZ. The active site of CheY comprises a cluster of three aspartic acid residues and a lysine residue, all of which participate in the binding of the Mg(2+) needed for the protein activation. Two steps were followed to study the activation mechanism of CheY upon phosphorylation: first, we independently substituted the three aspartic acid residues in the active site with alanine; second, several mutations were designed in helix alpha 4, both to increase its level of stability and to improve its packing against the protein core. The structural and thermodynamic analysis of these mutant proteins provides further evidence of the connection between the active-site area and helix alpha 4, and helps to understand how small movements at the active site are transmitted and amplified to the protein surface.

Selected figure(s)

Figure 3.
Figure 3. (a) Stereo diagram showing the superposition of D12A (green), D13A (blue), D57A (pink) over the apo-CheY structure (yellow; PDB entry 3CHY; [Volz and Matsumura 1991]). (b) Stereo representation of the area region around residue Leu98 in the mutant Hel43. Atoms interacting with the Leu98 side-chain are highlighted as spheres. The inner orientation of Tyr106 in the apo-CheY (PDB entry 3CHY; [Volz and Matsumura 1991]) is shown in darker thin bonds.

Figure 5.
Figure 5. (a) C^α tracing superimposition of mutant Hel43 (green) and apo-CheY (yellow; PDB entry 3CHY; [Volz and Matsumura 1991]). (b) Superposition of mutant Hel43 (green, with green labels) and apo-CheY (yellow, with red labels) at helix α4 and the preceding loop. (c) Skeletal and van der Waals representation of the region around residue 98 (blue spheres) in apo-CheY (PDB entry 3CHY; [Volz and Matsumura 1991]) and (d) in mutant Hel43 where alanine 98 has been replaced by a leucine residue.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2000, 303, 213-225) copyright 2000.

Figures were selected by an automated process.